Patients who present for scheduled (non-emergent) cesarean section will be given either intravenous dexamethasone or placebo prior to receiving a duramorph containing spinal anesthetic. The investigators will then compare the incidence of nausea and vomiting and the use of rescue anti-nausea medications in both groups. Our hypothesis is that patients receiving dexamethasone prior to duramorph containing spinal anesthesia for cesarean section will have a significantly lower incidence and severity of PONV at 0, 1, 3, 6, and 24 hours following surgery.